Keep in mind that this set of macros was intended to work with any combination of talents; thus, I tried to account for a variety of different playstyles.
To try and answer your question, I pulled Mind Blast (MB) out of the original all-in-one macro, because I wanted to make better use of the Shadowy Insight talent during PvP play.
As for Shadow Word: Death (SWD), I needed better control over this spell when Surrender to Madness was active.
As well, I should mention that I prefer these spells coded into macros (as opposed to on their own - uncoded), because it allows me to auto-target enemies faster and ensure that I never clip Void Torrent.
Thanks for picking my brain. I only hope this helps explain things better. ???